Mercury is a neurotoxic pollutant and contamination in remote ecosystems due to atmospheric mercury deposition coupled with watershed characteristics that influence mercury bioavailability. Biological interactions that affect mercury bioaccumulation are especially relevant as fish assemblages change in response to species introductions and lake management practices. We studied the influence of shifting food web dynamics on mercury in fisheries of Little Moose Lake in the southwestern Adirondack Mountains of New York, USA. Annual removal of non-native Smallmouth Bass (Micropterus dolomieu) has been used as a management strategy since 2000 to restore the native fish assemblage and food web in favor of Lake Trout (Salvelinus namaycush). Changes in total mercury, stable carbon (¹³C/¹²C) and nitrogen (¹⁵N/¹⁴N) isotopes, and growth were evaluated for Lake Trout and Smallmouth Bass. Growth rates increased for both predators and trophic position increased for Lake Trout post-removal. Mercury concentrations in Lake Trout increased over the 16-year study period influenced by a diet shift from invertebrates to higher trophic level prey fish, regardless of increased growth. Smallmouth Bass mercury concentrations decreased with compensatory growth from a reduced population size. These contrasting trends indicate that changes in mercury deposition were not the primary driver for mercury bioaccumulation responses in Little Moose Lake. Stable isotope values changed for both predators and for several lower trophic level organisms, likely reflecting changes in nutrient cycling and/or inputs. Our findings emphasize the potential role of fisheries management on whole-lake and predatory fish responses to mercury contamination in temperate lakes.

汞是一种神经毒性污染物，由于大气中的汞沉积以及影响汞生物利用度的分水岭特性，在偏远的生态系统中受到污染。随着鱼类种类因物种引进和湖泊管理实践而变化，影响汞生物累积的生物相互作用尤其重要。我们研究了食物网动态变化对美国纽约西南部阿迪朗达克山脉小麋鹿湖渔业中汞的影响。自2000年以来，每年都将非本地化的小嘴鲈鱼（Micropterus dolomieu）用作管理策略，以恢复本地鱼群和食物网，以支持鳟鱼湖（Salvelinus namaycush）。总汞，稳定碳的变化（¹³ C / ¹² C）和氮气（¹⁵ N / ¹⁴N）同位素，并评估了鳟鱼湖和小嘴鲈鱼的生长。捕食者的生长速度均增加，而鳟鱼撤离后的营养位置增加。鳟鱼湖中的汞浓度在16年的研究期内有所增加，这是由于从无脊椎动物到营养级较高的猎物的饮食变化（无论其增长如何）所致。小口黑鲈的汞浓度随着种群的减少而随着补偿性生长而降低。这些相反的趋势表明，汞沉积的变化并不是小麋湖中汞生物累积反应的主要驱动力。捕食者和几种低营养水平生物的稳定同位素值都发生了变化，这很可能反映了养分循环和/或输入的变化。